Hardener composition for epoxy resins

Abstract

A composition which consists essentially of the following components:A1) polyamines of formula (I) and/or (II) ##STR1## wherein R.sub.1 and R.sub.2 are each independently of the other a hydrogen atom or a methyl x is an integer from 1 to 3, and y is an integer from 0 to 2, the sum of x and y being up to and including 4, and z is an integer from 0 to 2; orA2) a mixture of polyamines of formula (I) and/or (II) with further polyamines; B) an aliphatic, cycloaliphatic or araliphatic alcohol or a mixture of corresponding alcohols; and C) an alkyl- and/or aralkyl-substituted monophenol or a mixture of corresponding monophenols, component C) constituting 20 to 50 percent of the total weight of the cited components. The compositions are useful as hardeners for epoxy resins to give cured material of particularly good resistance to chemicals.

Claims

1. A composition which consists essentially of the following components:

A1) polyamines of formula (I) or (II) ##STR5## wherein R.sub.1 and R.sub.2 are each independently of the other a hydrogen atom or a methyl group x is an integer from 1 to 3, and y is an integer from 0 to 2, the sum of x and y being up to and including 4, and z is an integer from 0 to 2; or

A2) a mixture of polyamines of formula (I) or (II) with further polyamines; B) an aliphatic, cycloaliphatic or araliphatic alcohol or a mixture of corresponding alcohols; and C) an alkyl- or aralkyl-substituted monophenol or a mixture of corresponding monophenols, component C) constituting 20 to 50 percent of the total weight of the cited components.

2. A composition according to claim 1, wherein component A1) or A2) is a polyamine mixture obtained by reacting a condensate of aniline and/or o-toluidine and formaldehyde, consisting of 85 to 50% by weight of corresponding dinuclear condensates and 15 to 50% by weight of corresponding tri- and polynuclear condensates, with hydrogen at a pressure of 3.5 to 27.7 MPa (500 to 4000 psig) and in the temperature range from 150.degree. to 250.degree. C. in the presence of a hydrogenation catalyst over 1 to 4 hours, and partially or completely isolating any undesirable components.

3. A composition according to claim 1, comprising as polyamines a mixture of 20 to 40% by weight of 2,4-bis(4-aminocyclohexylmethyl)cyclohexylamine; 40 to 70% by weight of 2,4-bis(4-aminocyclohexylmethyl)aniline; 0 to 10% by weight of bis(4-aminocyclohexyl)methane and, optionally, further tetranuclear or polynuclear polyamines, optionally 10 to 20% of all amino groups being aromatic.

4. A composition according to claim 1, wherein additional aliphatic, cycloaliphatic or araliphatic polyamines are admixed with the polyamine component A1) or A2).

5. A composition according to claim 1, containing the polyamines A1) or A2) in an amount of 30-70% by weight.

6. A composition according to claim 1, containing component B) in an amount of 20 to 50% by weight, based on the total weight of the polyamines as well as of components B) and C).

7. A composition according to claim 1, containing component A1) or A2) in an amount of 40 to 60% by weight, component B) in an amount of 15 to 25% by weight and component C) in an amount of 25 to 40% by weight, based on the total weight of components A1), B) and C), the sum of all these percentages being 100.

8. A composition according to claim 1, wherein component B) consists of furfuryl alcohol or benzyl alcohol or a mixture thereof.

9. A composition according to claim 1, wherein component C) consists of one or more than one monophenol, each carrying one, two or three substituents selected from alkyl groups containing 3 to 18 carbon atoms or from phenylalkyl groups.

10. A composition according to claim 9, wherein the monophenols carry an alkyl substituent of 9 to 12 carbon atoms or a substituent of formula ##STR6##

11. A composition according to claim 10, wherein the monophenol is p-nonylphenol or p-dodecylphenol or a mixture thereof.

12. A hardener for epoxy resins consisting of a composition according to claim 1.

13. A composition according to claim 10, wherein the monophenols carry an alkyl substituent of 9 to 12 carbon atoms or a substituent of formula ##STR7## which is in para-position to the hydroxyl group of the phenol.